The Hotshot II, Cool But Flawed(Now With Traxxas Parts!)

[MadAnt 71]

I'm sure if you look it up, you can find anyone that owns a new or old one of these 4WD Hotshot's or Hotshot 2's that will say many good things about them. The stuff not many people talk about though is how awful the design is. I mean it's still a cool buggy, but man! It's like one or a few of the engineers at Tamiya needed the crayons taken away.

Some time ago I bought a second hand Hotshot 2, it was before the it had re-release, maybe 6 or so years ago. I completely gone through it, cleaned everything and got it to be a fully functional buggy again. It was not in the best of shape, but it was now clean and good looking from 10 feet away. Knowing that what parts would interchange from other Tamiya models and parts availability at the time, I was not worried about lightly running it. I had some fun with it for a little bit of time and always kept it clean, I even upgraded the motor and speed controller and had it running pretty fast. I eventually put on the shelf and sort of forgot about it.

Now here in 2024, I feel like making the old Hotshot 2 a runner again. So while taking care of a few things on it, I was reminded of how questionable of how some of the "features" were designed. Although some of these designs were carried over from the original Hotshot, it was clear that these were some of the things that needed drastic improvement. Maybe Tamiya had some new engineers and rather than using the crayons to draw new much better disigns, they were eating them instead. Anyway, while I was installing some new electronics, I was reminded of how bad the design of the radio tray/box is. It's cramped and I'm sure with an ESC it gets hot due to the lack of air flow. Yes, I know, the temps may have been fine when it had an MSC, but it's still cramped and very annoying to deal with. They kept the little hatch, ok, that's cool, but could something be done about the drive shaft? I've been doing this hobby and other real life mechanical repairs long enough to know that the wires I tied in there may not stay put all the time. A simple shield around the driveshaft would have been a major improvement, but you know it's the zip ties and tape those engineers have faith in. 

Since I'm running new modern electronics and I don't want my receiver in the same hot room as the new Hobbywing 1060 ESC(I fried my Tazer ESC) I've relocated the receiver to small space under the molded driver in the chassis.

I'm sure it would have been fine in the same compartment, but this just seemed to work and with some creativity the plastic packaging from the Hobbywing esc becomes a pretty neat self for the receiver and stays there pretty good with servo tape.

I rambled long enough about one flaw, time for the next one, and it's a big one. The front bumper on this RC buggy somehow looks goofy and like it belongs there at the same time. I kind of dig it's big goofy appearance, but I have one major issue with it. IT'S MADE OF HARD PLASTIC! Both the front bumper and lower bracket should have been redesigned or improved to withstand any higher speed impacts. Tamiya could have used the same ABS blend that is used in the more flexible bumpers used on many of their other models, like the Blackfoot or the Frog. So now I have to glue the bumper bracket back together with some styrene for now until I get new parts. Ok, fine, l can still enjoy running the Hotshot 2. No big deal right now. 

If you have seen the photos, you will find that I'm running the 17 turn Method SV2 brushed motor from Team Orion. It's a bit slower than the Reedy Radon I had in it, but I don't like how hot the Radon gets, which is why a cut a hole in the can. Slowing things down should mean reduced chances of breaking stuff and since I already have a couple of these Method motors in my motor pile, I don't have buy a new motor and still be faster than stock. 

Test drive time! It was now night, so I went to the lit parking lot at the local grocery store. I plugged in my old Venom 4000Mah 20C oval lipo pack and did some zooming passes. It was still pretty fast and the old motor was still pretty responsive. The Hotshot 2 would crisply accelerate with no violence. With the Duratrx Bandito tires transferring the power into forward movement it was quick, almost brushless power quick. Things were going great, despite the buggy's flawed sloppy front suspension when drooped, it was running as straight as an arrow. I decided to do some curb hopping, nothing hard or big, infact the suspension never bottomed out. Unfortunately after just running for a very short time my run came to an end when the right rear dog bone shaft came out. Upon inspection I noticed that three of the rear control arms had broke. I really did not run it hard and the plastic at the hinge pins just gave up. One of the biggest flaws with the Hotshot 2 and other models using similar parts is the brittle plastic suspension arms. They could have been made a bit more beefy in certain areas or used a different ABS. Maybe they just got weaker over time, but they were just fine 6 years ago, it's a bummer. Well... now I wait for the new parts to come, thinking maybe I should find some replacement parts that are a bit more heavy duty and a bit more flexible.

I'll update when I fix it.

 

[Grumpy pants 5245]

Good looking buggy, great write up.

It’s a disappointing when brittle plastic stops play, I’ve read before the HS series can be a bit of a pain to work on. 

[Mad Ax 10130]

Yeah, cool but flawed - that's about right!

I had an original HotShot back in the 90s.  Well, it never ran, I was given it as a box of parts, none of them good enough to make a running car.  I sort of got it mostly together, so I could look at it, but it would fall apart as soon as I touched it.

It didn't have the original chassis - instead it had a custom-made one, or maybe a genuine TMS or Jim Davis chassis.  I don't have any pics of that car to compare, and it was given away long, long before I got back into RC.

When the re-re first came out, I knew I had to get one, to experience what I'd missed in the 90s.  It ran great - running over smooth grass, it was a joy to drive and looked awesome.  I could really see the suspension moving around and complying over the ground, much more than I could with my DF-03.  But after its first ever run, without any big jumps, that crazy over-engineered front shock was starting to banana.  That's exactly what had happened to my old one.  So, after just one run, the HotShot re-re got put on the shelf.

Fast-forward over a decade, and I rebuilt it with my own take on the TMS chassis, and with 4 shocks all round using brackets from RadShape RC.

I also don't like the stupid wide bumper, but when I raced my HotShot last year I kept it fitted because it does offer a little protection for those fragile front arms, and I crash a lot.  Actually I've yet to break an arm on the HotShot - so far I've only had a couple of steering hubs die where the balljoint threads have pulled out.

You can find out about my custom chassis here.  It is officially way easier to get to the electrics, although it's still seriously cramped!:

 

[BuggyDad 5388]

Considerable similarities between @Mad Ax's homemade chassis there and my more recent Boomerang one. 

Same material even. Mine incorporates M-05 steering parts and uses various 3d prints to hold it all together. I haven't tested it much but it should be robust. 3d printing is only used in areas/ways it should not be a weak link. I haven't a HS but I think the gearboxes, and therefore chassis fitment, are all the same? 

My other main area for strength improvement is bracing across suspension pins left to right. But again this isn't a choice borne out of personal experience with this chassis, rather of other tamiya chassis with suspension mounts built into the gearbox halves. 

[MadAnt 71]

10 hours ago, Mad Ax said:

Yeah, cool but flawed - that's about right!

I had an original HotShot back in the 90s.  Well, it never ran, I was given it as a box of parts, none of them good enough to make a running car.  I sort of got it mostly together, so I could look at it, but it would fall apart as soon as I touched it.

It didn't have the original chassis - instead it had a custom-made one, or maybe a genuine TMS or Jim Davis chassis.  I don't have any pics of that car to compare, and it was given away long, long before I got back into RC.

When the re-re first came out, I knew I had to get one, to experience what I'd missed in the 90s.  It ran great - running over smooth grass, it was a joy to drive and looked awesome.  I could really see the suspension moving around and complying over the ground, much more than I could with my DF-03.  But after its first ever run, without any big jumps, that crazy over-engineered front shock was starting to banana.  That's exactly what had happened to my old one.  So, after just one run, the HotShot re-re got put on the shelf.

Fast-forward over a decade, and I rebuilt it with my own take on the TMS chassis, and with 4 shocks all round using brackets from RadShape RC.

I also don't like the stupid wide bumper, but when I raced my HotShot last year I kept it fitted because it does offer a little protection for those fragile front arms, and I crash a lot.  Actually I've yet to break an arm on the HotShot - so far I've only had a couple of steering hubs die where the balljoint threads have pulled out.

You can find out about my custom chassis here.  It is officially way easier to get to the electrics, although it's still seriously cramped!:

 

Just read your whole build, 10 out of 10.

[MadAnt 71]

Well... sometimes I don't want to wait and sometimes parts from other stuff look like they could fit with some modifications. Lol, I'll let everyone guess what I did from the photos.

 

Just keep in mind that it's untested, I'll update in a day or two hopefully.

Edit:

Ok, lol, I'll tell ya'll. I took a pair of Traxxas Bandit rear control arms and modified them to fit on the Hotshot II. If all this works, I will follow up with a guide, this should be sorta easy to replicate if you have the right tools.

 

[Elbowloh 1234]

I bought one on impulse (Blockhead Motors version) then started collecting some hop ups. 

It sat there gathering dust and needed some cash for something else, so sold it all. 

Regretting it a little now.

[MadAnt 71]

A bit of an update...

I ran the car during lunch with the Bandit arms to see how things go. Since the biggest thing I can jump off of is a 5-6 inch curb I had to change my driving style to see if I can run into trouble with the new control arms. So... on dusty asphalt I drove the poor Hotshot II like a mad man. I would get up to speed, slam on the brakes and fling the car into an 180 and punch it. I was trying to see what those control arms could hold up to, whipping the car back and forth and getting into little drifts. There was not much deflection in those Traxxas control arms, they seemed to be doing well, even after a violent rollover, they held up. I was impressed. So maybe for another test in the future, maybe I can get this thing on a track and see how the Traxxas parts hold up after jumping off the bigger ramps. So stay tuned!In the picture above there seems to be enough room between the shock and the motor. I made sure that the angle was not too much for the operation of the shocks and that the ride hight and travel was still good with the new mounting position.

If you look close in the images below, you can see that I used different rear knuckles/uprights, they are the stock uprights for my TL01 that I had in my parts bin.

More updates!

I ran the Hotshot 2 after work going through another 2S lipo and I was thrashing it. Other than the bumper coming off again, the buggy held up fine, even after a few more violent scrambled egg rollovers. What a machine it was, probably reaching speeds in the 20-25 MPH range. Now I can sorta have fun with this thing and keep all the dog bone shafts in.

Even though it is fun to slide around, it becomes apparent that while on a surface with less grip the factory suspension configuration is not ideal if you want it to handle well. I can see the issue as the car turns and then spins out when the weight transfers. It's the front mono shock and swaybar. If I could just fit a stiffer front sway bar, a good amount of it's oversteer could be reduced, which would help the handling. I have some piano wire, I'll check if it's thicker and see if I can make a new sway bar. If not, maybe put some shock towers on the car and convert it two use a two shocks in the front rather than sharing one for both sides. Anyway, that's for the future, for now I want to fix the broken stuff, like the front bumper and the leaking front shock.

 

[MadAnt 71]

Ok, next up to fix is the front bumper, because it's awful and does not really absorb impacts that well from the front. So I went and picked up a sheet 3mm expanded PVC and 3mm ABS. I know it seems like a lot of material in the pic below, but the price was right and I can make many more things with what I have left.

The explanded PVC is very flexible, but I will need to bend and shape it to keep it from staying deformed, and the ABS will work great if I cut the right shape out of it. 

Stay tuned!

[MadAnt 71]

When you can't find what you're looking for, make it.

Ok, I have some progress for the front bumper. The first thing I addressed was the broken skid plate/mount. The styrene repair did not hold so I made a new more flexible and durable front skid plate out of 3mm ABS. It was a lot of cutting and grinding, but it came out good in the end and fits well using some bushings and other junk as spacers. Then I moved on to making the new bumper. When I was working with the expanded PVC, I realized it was too soft. So help the new bumper made from this softer material I also fabbed an inner ABS bumper just to stiffen things up, but yet still have flexibility. Next time I'll just fabricate the bumper out of ABS, which should be better depending on how I design it. Anyway, I'm gonna go easier on the car now on, I was only driving it hard to test out my modifications. I did not test the car tonight, but I kept punching the front for a bit to see how it hold up to that.

The new bumper is more narrow than the factory piece, which I think makes the Hotshot 2 look a bit less goofy than before.

 

[MadAnt 71]

Had some time again to run the hotshot 2 and see what else is going to break under normal driving. Two things I found that need addressing (other than a few cracks). First, the rear springs have a little too much preload. I did raise the ride height, but I did that by replacing the lower shock end/retainer, so the springs sit as they did before. Second, the screw fitment in the holes of the front sway bar mounts is not tight, so they have wiggle room and rely on the clamping force of the screws to not move a little bit. The problem is that the mounts can move just a little with a good whack, which will effect how the car sits causing it to not drive straight.

Ok, so other than fixing some old cracked plastics, those two flaws are the last things I want to fix. I will need to find some shorter springs, the rear springs are about the right amount of stiffness, but like I said, there is a little too much preload. Then for the sway bar brackets I have tightened the screws down with washers for more bite, but because the screws are in plastic, I don't like making the screws very tight and I might just use counter sink screws to center in the bracket holes.

Those are the spring retainers from my super clodbuster shocks. They are taller and give a little bit more room by the control arms.

[MadAnt 71]

My parts finally arrived, but I have already solved some of the issues. Hmmm... I guess I will start getting things ready to put together a tutorial for people who want better rear control arms on their Hotshot II/Boomerang or whatever else is related. 

Maybe I will make some more bumpers too, I have an idea for a jig tool to make the process easier.

[Grumpy pants 5245]

Coming along nicely 👏